GABA is the main inhibitory neurotransmitter in the adult brain. GABRA3 is a candidate gene for autism.
GABA-A receptor, Beta-3 Polypeptide (GABRB3) maps to chromosomal region 15q11.2-q12 in humans. GABA is the main inhibitory neurotransmitter in the adult brain. During neurotransmission GABA activates the GABA-A receptor on the postsynaptic neuron. When this happens, the GABA-A receptor changes shape – thereby opening a pore in the postsynaptic dendrite. This allows chloride ions, which carry an electric charge, to enter the dendrite. As a result, the charge in postsynaptic dendrite becomes more negative, which makes it more difficult to generate an action potential. This is one of the fundamental processes of learning. Because abnormalities in the levels of GABA have been found in individuals with autism, it is logical to examine whether polymorphisms in GABA receptor genes can contribute to the disorder. GABRA3 has become a candidate gene for autism, but findings have been somewhat mixed.